Injury Evaluation DeepensWith Echo Arcing Technique

July 1999
By Maryann Lawlor
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New dimension of medical imaging explored for today’s soldiers, tomorrow’s astronauts.

Lightweight ultrasound technology that captures three-dimensional images may help determine the extent of internal bleeding of injured soldiers on the battlefield at least 40 times faster than current equipment. Although the capability to acquire these pictures has been achieved in the past, a system currently being developed by a medical center under contract with the U.S. Defense Department would put this medical service closer to the front lines by making the equipment easily portable.

Experts believe this advanced technology will not only assist in the triage process in the military, but will have civilian applications as well. Additional research on other three-dimensional applications used in collaborative environments could one day support colonists on other planets.

Like most telemedicine techniques in use or being cultivated, the goal is to bring specialized care to the trauma site without transporting the expert to the location. It extends the reach of health care professionals while enlarging the footprint of medical resources. Whether employed for real-time videoconferencing or for collecting data to store and forward, these technologies, enabled by telecommunications lines, bring medical personnel more diagnostic information and provide patients with focused treatment.

Under a three-year, $3 million contract, the Lerner Research Institute, Cleveland, has been tasked with creating a new ultrasound scanner. The enhanced apparatus would be lighter than previous three-dimensional (3-D) ultrasound equipment and require less training to operate, making it more useful in military situations. The institute is part of the Cleveland Clinic Foundation and is working with the U.S. Army Medical Research and Materiel Command’s Telemedicine and Advanced Technology Research Center (TATRC), Fort Detrick, Maryland. The Cleveland Clinic Foundation, a private, nonprofit group practice, integrates clinical and hospital care with research and education.

The most common ultrasound technology involves sending high frequency sound waves through the body and collecting images as they bounce off the various densities of organs inside. Traditional scanners measure in the two-dimensional (2-D) plane, so radiologists had to acquire specific skills to read the images the ultrasound technician had recorded. “The person who reads the films is at the mercy of the ultrasound technicians, and if the radiologist can’t read them, then they have to be redone either by the technician or the doctor,” Maj. John J. Bauer, USA, director of surgical technology, TATRC, explains.

In September 1994, working with the U.S. Army Medical Research and Materiel Command, and with funds provided by the Defense Advanced Research Projects Agency, the Pacific Northwest Laboratories operated by Batelle in Richland, Washington, began developing one of the first 3-D ultrasound scanners. The medical ultrasound three-dimensional and portable with advanced communication (MUSTPAC) system was evaluated in July 1996 at the 212th Mobile Army Surgical Hospital, Camp Bedrock, near Tuzla, Bosnia.

According to Maj. Bauer, MUSTPAC is based on the acquisition of multiple 2-D ultrasound images. Using specially developed software, these images are then stacked to create the 3-D picture. A virtual ultrasound probe allows a radiologist to move around within the captured images to view the collected data set, producing the 3-D effect. However, this tool posed several problems, including its weight and, at times, unpredictability. Previous systems also could be ineffective at collecting images of moving organs such as the heart. “It was garbage in, garbage out, and it weighed a lot so a medic probably wouldn’t be able to carry it around. But it was good as a proof of concept that this type of thing could be done,” he says.

Using fine-tuned aperture technology, the equipment now being designed transmits an echo that arcs from transducer to transducer rather than bouncing sound waves off internal body structures. In addition, the components can be miniaturized so a number of images can be captured at one time, Maj. Bauer explains.

“In 2-D ultrasound, it takes a certain amount of time to collect data—sounds bouncing there and back. Three-dimensional ultrasound can be 40 to 80 times faster in collecting data, and it collects 3-D information for the data set right away, so there is no software to coordinate the data,” he offers.

This refined approach offers several benefits that specifically apply to the battlefield environment where specialized medical personnel are not readily available. “All [medics] have to do is use the probe and collect the data set and, because the information is acquired so quickly, it can be sent in near real time or stored and forwarded. A radiologist at a remote location can read the ultrasound data, make a diagnosis and recommend treatment. The information is of sufficient quality that it’s as if the patient is right in front of him,” Maj. Bauer says.

In situations where multiple trauma cases come to a medical station at one time, the equipment can be used as an evaluative tool in a triage situation to save valuable time. “There are various different injuries in the battlefield, so you have to do triage. If you have indications of internal bleeding, it is a serious condition, but the medic can’t detect this. It’s not like external bleeding that you can see. It can be difficult to assess, so the medic can’t be expected to evaluate this. Three-dimensional ultrasound allows diagnosis so the patient can go directly to the level of care required instead of going through four levels of evaluation to determine where he should go,” Maj. Bauer explains. This technique also applies in civilian medical emergency situations, he adds.

The National Aeronautics and Space Administration (NASA) has conducted substantial research into telemedicine and is using 3-D technologies to collaborate in the virtual environment. The agency views this as a way to respond to emergencies that could take place in space on the international space station or other spacecraft. Looking toward future colonization of other planets, NASA also believes telemedicine will address the beginning years of inhabiting other planets where extensive medical treatment may not be available.

This spring, doctors at five different sites in the United States, using 3-D medical images carried by a high-capacity network, demonstrated the use of NASA telemedicine to diagnose medical conditions, practice surgery and train medical personnel. During the presentation, physicians used scanned images of patients’ hearts, skulls and other body parts, and doctors at each site were able to view every procedure in three dimensions as each manipulated the image of the virtual patient.

The Virtual Collaborative Clinic linked medical personnel from the Cleveland Clinic; the Stanford University Medical Center and Salinas Valley Memorial Hospital, both in California; the Northern Navajo Medical Center, Shiprock, New Mexico; and NASA’s Ames Research Center, Moffett Field, California.

According to Dr. Muriel Ross, director, Center for Bioinformatics, Ames Research Center, the 3-D actual patient images used during the one-hour collaborative demonstration were acquired using computerized axial tomography and echocardiography. Doppler technology provided the images of the blood flow.

While Ross describes the event as a “smashing success,” she says it is important for both the medical and technical communities to realize that in some cases commercial technology is not fully developed, so making this kind of effort as an everyday occurrence is not yet possible. The medical aspects of the exercise took considerable energy, but the communications technology that had to be set up to support the event was astonishing in its own right, she offers.

“This is the first time something like this has been done, and we consider this a baby step because five years from now this kind of collaboration will be seen in many places,” she says. The demonstration was referred to as an experiment because the coordinators were never sure of exactly what would happen, she adds.

Commercial software has not been developed to support this type of medical endeavor, so scientists at Ames designed their own programs. In creating technologies for medical applications, Ross believes it is crucial to consider the users first. “Where companies fail is that they develop fine technology, but they don’t fill the needs in the community that it is serving. You have to keep it simple. You can’t come up with anything that’s complicated or people won’t use it,” she declares.

The center staff plans to conduct another virtual collaborative event, and other organizations have contacted Ross to participate in the next demonstration. She believes a different set of facilities will be used but plans to include the Northern Navajo Medical Center again because it represents a truly remote site.